Light emitting diode having silicon carbide layers

Abstract

A light emitting diode has a substrate body consisting of silicon carbide, which is transmissive for the luminescent radiation generated by the diode. The diode has a first epitaxially deposited layer, consisting of silicon carbide of a first conductivity type, disposed on the substrate body, and a second epitaxially deposited layer of silicon carbide of a second conductivity type disposed on the first layer. The diode has one electrode connected to the second layer and another electrode connected to an exposed portion of the first layer.

We claim as our invention: 
     
       1. A light emitting diode comprising: a silicon carbide substrate body;   an intermediate epitaxial layer consisting of silicon carbide of a first conductivity type grown on said substrate body;   an upper epitaxial layer consisting of silicon carbide of a second conductivity type grown on said first layer;   each of said epitaxial layers having an electrode directly connected thereto for biasing said diode; and   said substrate body being doped such that said substrate body is substantially transparent for radiation generated at a junction between said intermediate layer and said upper layer upon the application of bias current to said electrodes.   
     
     
       2. The light emitting diode of claim 1 wherein said intermediate layer is doped with aluminum for generating said first conductivity type and wherein said upper layer is doped with aluminum and nitrogen for generating said second conductivity type, said nitrogen doping predominating said aluminum doping. 
     
     
       3. The light emitting diode of claim 1 wherein said electrode connected to said intermediate layer is connected laterally at a side thereof. 
     
     
       4. The light emitting diode of claim 1 wherein said upper layer has an aperture therein exposing a portion of said intermediate layer at which one of said electrodes is connected to said intermediate layer. 
     
     
       5. The light emitting diode of claim 4 wherein said aperture is a recess at a side of said intermediate and upper layers. 
     
     
       6. The light emitting diode of claim 4 wherein said aperture is a hole-like aperture. 
     
     
       7. The light emitting diode of claim 1 wherein said upper layer is in the form of a mesa structure disposed on said intermediate layer.